Experiencing menstrual bleeding

Impurity is applicable even for a drop the size of a mustard seed: Megillah 28b
"Madlefet"- dripping blood: Niddah 10b

The Blood's Source

Blood from a wound: Niddah 16a
To what point does the blood have to emerge, for a woman to be a Niddah: Makkot 14b
Whether all blood of the uterus (Mekor) is automatically impure, and "pure" bleeding [as that of a pregnant woman] occurs from elsewhere, or not: Niddah 16a, 22a, 41b, 66a, 71a
Blood from the various sections of the internal genitalia: Niddah 17b
Blood which is discovered in the exiting area, and so may be from any of the internal sections: Niddah 17b-18a
Assuming that genital bleeding came from the area where most genital bleeding comes from: Niddah 18a
How we know that there is blood which is not impure: Niddah 19a

Checking for Blood

How to check a young girl internally: Niddah 10b

General Rules of "Retroactive" Status when Bleeding is Discovered

The credibility of a rag with which a woman wiped herself before sexual relations: Niddah 5a
Whether we assume that she became menstruant only recently, or whether it is retroactive to the most recent examination: Niddah 2a-7a, 15a
The Above case, where she has a set time, ordinarily, for seeing blood: Niddah 2a, 4b-5a, 9b, 63a
The retroactive status of a woman who finds blood, and had been using a contraceptive [potentially absorptive] rag during sexual relations: Niddah 3a-b

The Beginning of Menstruation

Definition of "seeing blood for the first time": Niddah 7b
The status of a woman during her first 3 bleedings, if she is of age for bleeding: Niddah 9b
The retroactive status of a woman who is experiencing menstrual blood for the first time: Niddah 4b, 7a
The retroactive status of a woman who is experiencing menstrual blood for the second time: Niddah 10b-11a

An Underage Menstruant

While a woman is underage, it is assumed that she has not experienced bleeding. Once she is of age, it is assumed that she has experienced it: Niddah 10b
A young girl who experiences bleeding before she is of age: Niddah 9b, 10b
A woman who is underage and experiences an outpouring of blood: Niddah 10b
A young girl who experiences bleeding with 90-day intervals, 3 times: Niddah 9b
What if a woman is underage, and experiences bleeding with 90-day intervals, and then begins bleeding during the intervals: Niddah 9b-10a
The retroactive status of a woman who is experiencing menstrual blood for the first time, but is underage for such blood: Niddah 5a

Hymenal Blood

A woman who has never experienced menstrual bleeding, and now experiences hymenal bleeding or birth-bleeding: Niddah 8b
How many days a woman is assumed to be experiencing only hymenal bleeding, if she marries while underage for menstrual bleeding: Niddah 11b, 64b
The Above, where she stops bleeding at some point following the initial hymenal bleeding, and then re-starts; or where the color of her blood changes: Niddah 11b

Blood During Pregnancy

Definition of "pregnancy": Niddah 7b
The retroactive status of a woman who is pregnant and sees menstrual blood: Niddah 4b, 7a
The retroactive status of a woman who is pregnant and sees menstrual blood a second time: Niddah 10b-11a
A woman who experiences bleeding, but then discovers that she is pregnant [and so this can't be menstrual blood]: Niddah 9a
A pregnant woman who experiences bleeding with 90-day intervals, 3 times: Niddah 10b
Counting part of pregnancy together with part of nursing, towards the total time when she skips menstrual bleeding to establish herself as a non-bleeder: Niddah 10b

Birthing-Blood

A woman who has never experienced menstrual bleeding, and now experiences hymenal bleeding or birth-bleeding: Niddah 8b
A woman who is known to be pregnant, and then experiences bleeding and births an insubstantial item: Niddah 8b-9a
Considering birthing-blood to be separate from menstruant blood, for legal issues: Niddah 10b

Blood During the Nursing Period

Definition of "nursing": Niddah 7b
The retroactive status of a woman who is nursing and sees menstrual blood: Niddah 4b, 7a
The retroactive status of a woman who is nursing and sees menstrual blood a second time: Niddah 10b-11a
What if the nursing child dies, and the mother experiences bleeding during what would have been the first 24 months of the child's life: Niddah 9a
What if a mother continues nursing her child after 24 months, and experiences bleeding: Niddah 9a
A nursing woman who experiences bleeding with 90-day intervals, 3 times: Niddah 10b
Counting part of pregnancy together with part of nursing, towards the time when she skips menstrual bleeding to establish herself as a non-bleeder: Niddah 10b

Post-Menopausal Bleeding

Definition of "post-menopausal": Eruvin 46a; Niddah 7b
At what age a woman is considered "old" for these laws: Niddah 9a-b
The retroactive status of a woman who is post-menopausal and sees menstrual blood: Eruvin 46a; Niddah 4b, 7a
The retroactive status of a woman who is post-menopausal and sees menstrual blood a second time: Niddah 10b-11a
How long a woman must go without seeing blood, before she is considered "old": Eruvin 46b; Niddah 9b
What if an aging woman goes 90 days between seeing blood, 3 consecutive times: Niddah 9b
What if an aging woman goes 90 days without bleeding, but it's explicable by a non-geriatric issue: Niddah 9b

Other Cases

The retroactive status of a cheresh who finds menstrual blood: Niddah 3a